Head Catherine E I, Koldewey Heather, Pavoine Sandrine, Pratchett Morgan S, Rogers Alex D, Taylor Michelle L, Bonsall Michael B
Department of Zoology University of Oxford Oxford UK.
Conservation Programmes Zoological Society of London London UK.
Ecol Evol. 2018 Mar 26;8(8):4098-4107. doi: 10.1002/ece3.3969. eCollection 2018 Apr.
Coral reefs are the most biodiverse marine ecosystem and one of the most threatened by global climate change impacts. The vast majority of diversity on reefs is comprised of small invertebrates that live within the reef structure, termed the cryptofauna. This component of biodiversity is hugely understudied, and many species remain undescribed. This study represents a rare analysis of assembly processes structuring a distinct group of cryptofauna, the Palaemonidae, in the Chagos Archipelago, a reef ecosystem under minimal direct human impacts in the central Indian Ocean. The Palaemonidae are a diverse group of Caridae (infraorder of shrimps) that inhabit many different niches on coral reefs and are of particular interest because of their varied habitat associations. Phylogenetic and trait diversity and phylogenetic signal were used to infer likely drivers of community structure. The mechanisms driving palaemonid community assembly and maintenance in the Chagos Archipelago showed distinct spatial patterns. At local scales, among coral colonies and among reefs fringing individual atolls, significant trait, and phylogenetic clustering patterns suggest environmental filtering may be a dominant ecological process driving Palaemonidae community structure, although local competition through equalizing mechanisms may also play a role in shaping the local community structure. Importantly, we also tested the robustness of phylogenetic diversity to changes in evolutionary information as multi-gene phylogenies are resource intensive and for large families, such as the Palaemonidae, are often incomplete. These tests demonstrated a very modest impact on phylogenetic community structure, with only one of the four genes (PEPCK gene) in the phylogeny affecting phylogenetic diversity patterns, which provides useful information for future studies on large families with incomplete phylogenies. These findings contribute to our limited knowledge of this component of biodiversity in a marine locality as close to undisturbed by humans as can be found. It also provides a rare evaluation of phylogenetic diversity methods.
珊瑚礁是生物多样性最丰富的海洋生态系统之一，也是受全球气候变化影响威胁最大的生态系统之一。珊瑚礁上绝大多数的生物多样性由生活在珊瑚礁结构内的小型无脊椎动物组成，这些动物被称为隐栖动物。生物多样性的这一组成部分受到的研究极少，许多物种仍未被描述。本研究对印度洋中部查戈斯群岛一个受人类直接影响最小的珊瑚礁生态系统中构成一个独特隐栖动物群（虾蛄科）的组装过程进行了罕见的分析。虾蛄科是虾类（十足目下目）中一个多样的类群，栖息在珊瑚礁的许多不同生态位，因其多样的栖息地关联而特别受关注。利用系统发育和性状多样性以及系统发育信号来推断群落结构可能的驱动因素。在查戈斯群岛，驱动虾蛄科群落组装和维持的机制呈现出明显的空间格局。在局部尺度上，在珊瑚群体之间以及环绕各个环礁的珊瑚礁之间，显著的性状和系统发育聚类模式表明，环境过滤可能是驱动虾蛄科群落结构的主要生态过程，尽管通过均等化机制的局部竞争也可能在塑造局部群落结构中发挥作用。重要的是，我们还测试了系统发育多样性对进化信息变化的稳健性，因为多基因系统发育资源密集，对于像虾蛄科这样的大型科来说往往不完整。这些测试表明对系统发育群落结构的影响非常小，系统发育中四个基因中只有一个（磷酸烯醇丙酮酸羧激酶基因）影响系统发育多样性模式，这为未来对不完整系统发育的大型科的研究提供了有用信息。这些发现有助于我们对这个几乎未受人类干扰的海洋地区生物多样性的这一组成部分的有限认识。它还对系统发育多样性方法进行了罕见的评估。
